It is known that absorption of bacteria by dentin results in the formation of plaque on tooth surfaces. The buildup of plaque is the cause of caries and periodontosis. Systematic studies by Muhlemann, et al have shown that cations with a multiple positive charge exert a caries-protective effect. In particular, hydrophobic cations in such compounds as alkyl ammonium fluorides, demonstrate that the caries-protective effect must be attributed mainly to the cation rather than the fluoride anion.
Quaternary, long-chain compounds of this type possess considerable anti-microbial activity, as does sodium-palmitoyl-L-lysine-L-lysine ethyl ester dihydrochloride and sodium-palmitoyl-L-lysine-L-lysine amide dihydrochloride (e.g. German Pat. No. 1 154 236). Therefore, when used regularly, they can influence the composition of the oral microbial flora and alter it in an undesirable manner. Moreover, the toxicity of long-chain quaternary compounds is considerable and is a factor which cannot be ignored.
It is an object of the present invention to overcome the disadvantages associated with known caries-prophylactic compounds and to develop non-toxic substances which, in addition to inhibiting caries and periodontosis development, have, at the same time, a very low anti-microbial activity.
It is an additional object of this invention to provide suitable dental and mouth care preparations containing these substances.
It has now been found that esters, as well as their mono and double salts, of a certain diamino-monocarboxylic acid; namely, lysine (.alpha.,.beta.-diamino-n-caproic acid), exhibit a very good bacterial adhesion inhibiting effect combined with very low bacteriostatic activity and toxicity. This makes their use in dental and mouth care preparations especially valuable.
The use of such preparations in the mouth results in a decrease in the number of colony-forming units of bacterial oral flora on tooth surfaces. This effect is associated with a decrease in the formation of dental plaque which in turn results in a similar decreased tendency towards caries and periodontosis. Prevention of the formation of plaque and tartar is presently regarded as the most important means of preventing the spread of dental caries and periodontous diseases.